Mild to moderate physical dependence on ethanol will be instituted by schedule-induced ethanol polydipsia. Motor control in withdrawn rats will be used to evaluate the dependence. Ethanol elimination rates will be studied in severe dependence and with protein supplement. Cross-tolerance between ethanol and barbiturates will be evaluated by discriminative motor control performance and the disappearance rates of these substances from the blood will be tracked. The cross-dependence induced by cross-tolerance will be studied with regard to its possible role in cross-abuse. The possible protective effect of ethanol on the development of essential hypertension will be explored.